Hair dryers have been widely used to blow dry wet hair or other wet article. Conventionally, the hair dryer is powered by electrical energy which is converted into heat and which is also used to drive a fan for blowing hot air flow. Since generating hot air flow by converting electrical energy into heat would consume a great quantity of electricity, usually at least 500 W, the conventional hair dryer is designed to be powered by main electricity from, for example, a wall outlet. Such a design has several disadvantages, such as:
(1) Electrical voltage may be different from country to country which prohibits the general consumers to use their own hair dryers in traveling in different countries, unless an adapter or transformer is used.
(2) The conventional hair dryer may not be used at areas where no main electricity is supplied, such as camping in the wilds.
(3) Using the conventional hair dryer in a humid environment (such as in a bathroom) may have the risk of electrical shock.
Thus, it is desirable to provide a hair dryer that is not powered by electrical main so as to overcome such problems encountered in the prior art.